Redispersible microdenominated cellulose

Abstract

A process for the production of and a composition of redispersible mechanically disassembled cellulose and the resultant product, referred to as microdenominated cellulose (MDC). The process is characterized by drying the MDC in the presence of a dispersion agent. The product is characterized by a settled volume of greater than 50%, as determined on the basis of a 1% by weight suspension in water after twenty-four hours, and a water retention value of over 350%. MDC is useful as an ingredient in foods, pharmaceutical and cosmetic products.

What is claimed is: 
     
       1. A process for preparing dry, redispersible microdenominated cellulose comprising microdenominated cellulose prepared by repeatedly passing a liquid suspension of cellulose through a zone of high shear, said zone being defined by two confronting surfaces, with one of said surfaces rotating relative to the other, until said cellulose suspension is rendered substantially stable and has a Canadian Standard Freeness that consistently increases with repeated passage through said zone of high shear, said microdenominated cellulose having a settled volume of greater than 50% as determined on the basis of a 1.0% by weight suspension in water after twenty-four hours and drying said suspension of microdenominated cellulose in the presence of a dispersion agent in an amount effective to impart to said dry microdenominated cellulose a viscosity, when dispersed in water, of at least 50% of the viscosity of an equivalent concentration of never dried microdenominated cellulose dispersed in water. 
     
     
       2. A process according to claim 1 wherein said dispersion agent comprises maltodextrin and carboxymethylcellulose (CMC), the amount of said maltodextrin being about one-half to 1.5 times the weight of said microdenominated cellulose and the amount of said CMC being about of 5% to 15% of said weight of the microdenominated cellulose. 
     
     
       3. A process according to claim 1 wherein said suspension is dried as a substantially continuous film on a heated, moving belt dryer. 
     
     
       4. A process according to claim 1 wherein said suspension is dried as a substantially continuous film on a heated, double drum dryer. 
     
     
       5. A process according to claim 1 wherein lecithin is included in said dispersion agent in an amount from 0.1 to about 10% based on the weight of the microdenominated cellulose contained therein. 
     
     
       6. A composition comprising dry, microdenominated cellulose, said microdenominated cellulose being prepared by repeatedly passing a liquid suspension of fibrous cellulose through a zone of high shear, said zone being defined by two confronting surfaces, with one of said surfaces rotating relative to the other, until said cellulose suspension is rendered substantially stable and has a Canadian Standard Freeness that consistently increases with repeated passage through said zone of high shear, said microdenominated cellulose having a settled volume of greater than 50%, as determined on the basis of a 1.0% by weight suspension in water after twenty four hours and a water retention value greater than 500% and at least two dispersing agents, said dispersing agent consisting essentially of a first material selected from the group consisting of maltodextrins, complex polysaccharides, simple sugars and common edible disaccharides in an amount sufficient to form continuous encapsulating matrices on drying and a second material selected from the group consisting of CMC, locust bean gum, xanthan gum and guar gum in an amount sufficient to provide defloculating or repellant barriers between adjacent fibril surfaces, said amounts being effective to impart to said dry microdenominated cellulose a viscosity, when re-dispersed in water, of at least 50% of the viscosity of an equivalent concentration of never dried microdenominated cellulose dispersed in water. 
     
     
       7. A composition as claimed in claim 6, wherein said dispersing agent of the first type is maltodextrin and the dispersing agent of the second type is carboxymethylcellulose. 
     
     
       8. A composition according to claim 7 wherein the amount of said dispensing agent of the first type is in the range of about 50% to about 150% by weight of the microdenominated cellulose. 
     
     
       9. A composition according to claim 7 wherein the amount of said dispersing agent of the second type is in the range of about 5% to about 15% by weight of the microdenominated cellulose. 
     
     
       10. A composition comprising dry, microdenominated cellulose, said microdenominated cellulose being prepared by repeatedly passing a liquid suspension of fibrous cellulose through a zone of high shear, said zone being defined by two confronting surfaces, with one of said surfaces rotating relative to the other, until said cellulose suspension is rendered substantially stable and has a Canadian Standard Freeness that consistently increases with repeated passage through said zone of high shear, said microdenominated cellulose having a settled volume of greater than 50%, as determined on the basis of a 1.0% by weight suspension in water after twenty four hours and a water retention value greater than 500% and a dispersion agent comprising maltodextrin and carboxymethylcellulose (CMC), the amount of said maltodextrin being about one-half to 1.5 times the weight of said microdenominated cellulose and the amount of said CMC about 5% to 15% of the weight of the microdenominated cellulose.